Re: [PATCH 3/3] drm/msm/dpu: Add interface support for CRC debugfs

On 27/05/2022 21:54, Jessica Zhang wrote:

Add support for writing CRC values for the interface block to the debugfs by calling the necessary MISR setup/collect methods.

Signed-off-by: Jessica Zhang quic_jesszhan@quicinc.com

drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 43 ++++++++++++++- drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h | 3 + drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 61 +++++++++++++++++++++ drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h | 22 ++++++++ 4 files changed, 128 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c index ae09466663cf..e830fb1e910d 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c @@ -79,6 +79,8 @@ static enum dpu_crtc_crc_source dpu_crtc_parse_crc_source(const char *src_name) if (!strcmp(src_name, "auto") || !strcmp(src_name, "lm")) return DPU_CRTC_CRC_SOURCE_LAYER_MIXER;

• if (!strcmp(src_name, "intf"))

• return DPU_CRTC_CRC_SOURCE_INTF;
  
  

  return DPU_CRTC_CRC_SOURCE_INVALID; }

@@ -94,8 +96,18 @@ static int dpu_crtc_verify_crc_source(struct drm_crtc *crtc, return -EINVAL; }

• if (source == DPU_CRTC_CRC_SOURCE_LAYER_MIXER)

• if (source == DPU_CRTC_CRC_SOURCE_LAYER_MIXER) { *values_cnt = crtc_state->num_mixers;
• } else if (source == DPU_CRTC_CRC_SOURCE_INTF) {

• struct drm_encoder *drm_enc = get_encoder_from_crtc(crtc);
  

Let's do this correctly from the beginning. The CRTC can drive several encoders. Do we want to get CRC from all of them or just from the first one?

• if (!drm_enc) {
  

• 	DRM_ERROR("no encoder found for crtc %d\n", crtc->index);
  

• 	return -ENODATA;
  

• }
  

• *values_cnt = dpu_encoder_get_num_phys(drm_enc);
  

• }

  return 0; }

@@ -116,6 +128,18 @@ static void dpu_crtc_setup_lm_misr(struct dpu_crtc_state *crtc_state) } }

+static void dpu_crtc_setup_encoder_misr(struct drm_crtc *crtc) +{

• struct drm_encoder *drm_enc = get_encoder_from_crtc(crtc);
• if (!drm_enc) {

• DRM_ERROR("no encoder found for crtc %d\n", crtc->index);
  

• return;
  

• }
• dpu_encoder_setup_misr(drm_enc);

+}

• static int dpu_crtc_set_crc_source(struct drm_crtc *crtc, const char *src_name) { enum dpu_crtc_crc_source source = dpu_crtc_parse_crc_source(src_name);

@@ -164,6 +188,8 @@ static int dpu_crtc_set_crc_source(struct drm_crtc *crtc, const char *src_name)

if (source == DPU_CRTC_CRC_SOURCE_LAYER_MIXER) dpu_crtc_setup_lm_misr(crtc_state);

• else if (source == DPU_CRTC_CRC_SOURCE_INTF)

• dpu_crtc_setup_encoder_misr(crtc);
  
  

  cleanup: drm_modeset_unlock(&crtc->mutex);

@@ -212,6 +238,18 @@ static int dpu_crtc_get_lm_crc(struct drm_crtc *crtc, struct dpu_crtc_state *crt drm_crtc_accurate_vblank_count(crtc), crcs); }

+static int dpu_crtc_get_encoder_crc(struct drm_crtc *crtc) +{

• struct drm_encoder *drm_enc = get_encoder_from_crtc(crtc);
• if (!drm_enc) {

• DRM_ERROR("no encoder found for crtc %d\n", crtc->index);
  

• return -EINVAL;
  

• }
• return dpu_encoder_get_crc(drm_enc);

+}

• static int dpu_crtc_get_crc(struct drm_crtc *crtc) { struct dpu_crtc_state *crtc_state;

@@ -227,6 +265,9 @@ static int dpu_crtc_get_crc(struct drm_crtc *crtc) if (crtc_state->crc_source == DPU_CRTC_CRC_SOURCE_LAYER_MIXER) return dpu_crtc_get_lm_crc(crtc, crtc_state);

• if (crtc_state->crc_source == DPU_CRTC_CRC_SOURCE_INTF)

• return dpu_crtc_get_encoder_crc(crtc);
  

• return 0; }

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h index b8785c394fcc..a60af034905d 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h @@ -1,5 +1,6 @@ /* SPDX-License-Identifier: GPL-2.0-only */ /*

• • Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
  • Copyright (c) 2015-2021 The Linux Foundation. All rights reserved.
  • Copyright (C) 2013 Red Hat
  • Author: Rob Clark robdclark@gmail.com

@@ -73,11 +74,13 @@ struct dpu_crtc_smmu_state_data {

• enum dpu_crtc_crc_source: CRC source
• @DPU_CRTC_CRC_SOURCE_NONE: no source set
• @DPU_CRTC_CRC_SOURCE_LAYER_MIXER: CRC in layer mixer

• • @DPU_CRTC_CRC_SOURCE_INTF: CRC in phys interface
  • @DPU_CRTC_CRC_SOURCE_INVALID: Invalid source
  */ enum dpu_crtc_crc_source { DPU_CRTC_CRC_SOURCE_NONE = 0, DPU_CRTC_CRC_SOURCE_LAYER_MIXER,
• DPU_CRTC_CRC_SOURCE_INTF, DPU_CRTC_CRC_SOURCE_MAX, DPU_CRTC_CRC_SOURCE_INVALID = -1 };

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c index 52516eb20cb8..7740515f462d 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c @@ -14,6 +14,7 @@

#include <drm/drm_crtc.h> #include <drm/drm_file.h> +#include <drm/drm_vblank.h> #include <drm/drm_probe_helper.h>

#include "msm_drv.h" @@ -225,6 +226,66 @@ bool dpu_encoder_is_widebus_enabled(const struct drm_encoder *drm_enc) return dpu_enc->wide_bus_en; }

+int dpu_encoder_get_num_phys(const struct drm_encoder *drm_enc) +{

• struct dpu_encoder_virt *dpu_enc;
• dpu_enc = to_dpu_encoder_virt(drm_enc);
• return dpu_enc->num_phys_encs;

+}

+void dpu_encoder_setup_misr(const struct drm_encoder *drm_enc) +{

• struct dpu_encoder_virt *dpu_enc;
• int i;
• dpu_enc = to_dpu_encoder_virt(drm_enc);
• for (i = 0; i < dpu_enc->num_phys_encs; i++) {

• struct dpu_encoder_phys *phys = dpu_enc->phys_encs[i];
  

• if (!phys->hw_intf || !phys->hw_intf->ops.setup_misr)
  

• 	continue;
  

Does WB support CRC?

• phys->hw_intf->ops.setup_misr(phys->hw_intf, true, 1);
  

• }

+}

+int dpu_encoder_get_crc(const struct drm_encoder *drm_enc) +{

• struct dpu_encoder_virt *dpu_enc;
• u32 crcs[MAX_PHYS_ENCODERS_PER_VIRTUAL];
• int i, rc;
• if (!drm_enc->crtc) {

• DRM_ERROR("no crtc found for encoder %d\n", drm_enc->index);
  

• return -EINVAL;
  

• }
• dpu_enc = to_dpu_encoder_virt(drm_enc);
• for (i = 0; i < dpu_enc->num_phys_encs; i++) {

• struct dpu_encoder_phys *phys = dpu_enc->phys_encs[i];
  

• if (!phys->hw_intf || !phys->hw_intf->ops.collect_misr)
  

• 	continue;
  

• rc = phys->hw_intf->ops.collect_misr(phys->hw_intf, &crcs[i]);
  

This doesn't look fully correct. Do we need to skip the indices for the phys without a backing hw_intf?

Extra empty line.

• if (rc) {
  

• 	if (rc != -ENODATA)
  

Do we need to handle ENODATA in any specific way (like zeroing the crcs[i])? If not, I'd suggest to drop this return code. Let's make an error always an error.

• 		DRM_DEBUG_DRIVER("MISR read failed\n");
  

• 	return rc;
  

• }
  

• }
• return drm_crtc_add_crc_entry(drm_enc->crtc, true,

• 	drm_crtc_accurate_vblank_count(drm_enc->crtc), crcs);
  

+}

• static void _dpu_encoder_setup_dither(struct dpu_hw_pingpong *hw_pp, unsigned bpc) { struct dpu_hw_dither_cfg dither_cfg = { 0 };

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h index 781d41c91994..8345599dd01a 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h @@ -1,5 +1,6 @@ /* SPDX-License-Identifier: GPL-2.0-only */ /*

• • Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
  • Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
  • Copyright (C) 2013 Red Hat
  • Author: Rob Clark robdclark@gmail.com

@@ -174,6 +175,27 @@ int dpu_encoder_get_vsync_count(struct drm_encoder *drm_enc);

bool dpu_encoder_is_widebus_enabled(const struct drm_encoder *drm_enc);

+/**

• • dpu_encoder_get_num_phys - get number of physical encoders contained in virtual

• •                        encoder
    

• • @drm_enc: Pointer to previously created drm encoder structure
• • Returns: Number of physical encoders for given drm encoder
• */

+int dpu_encoder_get_num_phys(const struct drm_encoder *drm_enc);

+/**

• • dpu_encoder_setup_misr - enable misr calculations
• • @drm_enc: Pointer to previously created drm encoder structure
• */

+void dpu_encoder_setup_misr(const struct drm_encoder *drm_encoder);

+/**

• • dpu_encoder_get_crc - get the crc value from interface blocks
• • @drm_enc: Pointer to previously created drm encoder structure
• • Returns: 0 on success, error otherwise
• */

+int dpu_encoder_get_crc(const struct drm_encoder *drm_enc);

• /**
  • dpu_encoder_use_dsc_merge - returns true if the encoder uses DSC merge topology.
  • @drm_enc: Pointer to previously created drm encoder structure